Civil War: House of M (2008 series) #4

In the skies over Genosha, Magneto fights Mimic who can copy the abilities of any mutant. Magneto claps an inhibitor collar from the museum on him and Mimic plummets to the ground where Magneto beats him to death with a metal post….

Inside the palace, Nuke fights his way through mutant guards until he reaches Wanda in her bedroom; she awakens and, displaying powers for the first time, she literally takes him apart….

Magneto rushes to the citadel to find Charles Xavier mortally wounded by the Winter Soldier’s blade. Xavier pleads for mercy before dying in Magnus’ arms. Bucky reveals himself and he attacks Magneto with non-metallic knife and gun; Magneto moves Captain America’s shield to block the bullets then hurls the shield to decapitate Bucky. Polaris and Quicksilver arrive with a report of casualties and Wanda shows up with the gravely wounded Sabretooth. Magneto holds Cap’s shield and notes that it was once the symbol of high ideals but now merely carries the colors of a doomed empire….

The White House is on lockdown, President Richard M. Nixon and Vice President Bolivar Trask under guard by a mass of Secret Service agents. Then Cap’s shield crashes through the window. Magneto and his army besiege the White House, taking on the new non-metallic Sentinels. Trask, on his way to the SHIELD Helicarrier, orders a nuclear strike on Genosha….